In the distributed video coding applications, such as video surveillance, the video cameras, often in an array of hundreds or even thousands of cameras, record scenes into video sources. The analog cameras output uncompressed video data (or raw video data); the digital cameras generate compressed video streams (such as MPEG4 and Motion JPEG coded streams). The compressed or uncompressed video data is then archived at a central storage center. Both the analog and digital cameras usually output the video at a fixed data rate, regardless of whether the output is compressed or not. Furthermore, even when the cameras compress the video, the encoders that the cameras equip usually do not employ a state-of-the-art codec. The compression efficiency is not good. For example, the most common digital video cameras encode the video using the old generation standard MPEG4 or Motion JPEG due to the low complexity, i.e., the low encoding cost requirement for the camera cost constraint. Thus, directly storing the outputs of the video surveillance cameras will incur a very high storage cost, especially when the number of cameras is large.
Statistical multiplexing has previously been used for transmission bandwidth sharing among multiple sources. The principle of statistical multiplexing is to dynamically allocate a share of the total available bandwidth according to certain statistics that reflect the signal characteristics of a source. For example, a source with higher information entropy or signal energy at a given time may be allocated a larger share of the bandwidth compared to a source with less information entropy or signal energy. The sum of the bandwidth shares of all sources being transmitted equals to the total transmission bandwidth available at the given time.